The present invention pertains to illuminated covers for devices such as cellular telephones. More particularly, the present invention pertains to decorative illuminated covers. The present invention also pertains to a cellular telephone having an illuminated cover, which might be a decorative illuminated cover. Additionally, the present invention pertains to a method of manufacturing an illuminated cover, including a decorative illuminated covers.
Portable electronic devices, such as cellular telephones, are becoming widely used. Many people desire to have a unique appearing portable electronic device, particular a cellular telephone, not only for its attractiveness, but also to enable them to identify their own phone or other device from devices belonging to other people.
People often have a cellular telephone when in locations in which the ringing of the telephone is undesirable. In such situations, the ringer of the telephone can be shut-off. However, if a call is placed to the telephone while the ringer is off, the user does not know about the call unless there is some other way to indicate its arrival. While some cellular telephones retain a visual indication of unanswered calls, indicating the calling number, the user of such a phone is unlikely to learn of the call until he or she happens to activate the phone next. This may be a considerable time after the call was placed. If the call related to time sensitive information, the user may lose the benefit of the information because he or she did not notice the call soon enough. While a number of light emitting diodes can be incorporated within the cover of a device such as a cellular telephone, so as to be illuminated in response to the ringing current of the telephone, because of power requirements it is impractical to provide an illuminated decorative pattern of light emitting diodes.
An electroluminescent foil can be utilized to provide a lighted pattern on a electronic device such as a cellular telephone. However, electroluminescent foils require high ac voltage, in the range of from about 20 volts to about 240 volts at from about 50 Hz to about 300 Hz. Consequently, the electroluminescent foil has to be insulated from the person utilizing the electronic device. Satisfactory insulation can be provided by placing the electroluminescent foil between two insulating foils, for example by laminating an insulating foil onto each surface of the electroluminescent foil. The combined foils then must be adhered to a support base shaped to provide the desired cover for the electronic device. Such a support base can be formed by placing the combined foils in a mold, and injecting plastic or other suitable material. By way of examples, U.S. Pat. Nos. 3,298,558, 4,330,578, 4,495,125, 4,994,224, 5,989,480, and 6,117,384, the disclosures of which are incorporated herein by reference, show techniques for molding plastic articles with decorative patterns.
It is necessary for the electroluminescent foil to be connected to a power source. Japanese Patent Publication 10-134960 dated May 22, 1998 shows a molded electroluminescent device having a flexible lead for connection to a power source. However, it is difficult to provide a flexible lead for such connection when the combined foils are adhered to the rigid support base by molding. Frequently, the flexible lead is damaged or destroyed during the molding process, resulting in considerable waste.
The present is an illuminated cover and a covered electronic device such as a cellular telephone. In addition, the present invention is a method of manufacturing a illuminated cover. An illuminated cover in accordance with the present invention has a predetermined shape and includes a thin, rigid support base shaped in accordance with the predetermined shape. An electroluminescent insulating foil overlies a first surface of the support base. An insulating foil overlies the electroluminescent foil. If desired, a graphic can be positioned between the insulating foil and the electroluminescent foil. A second insulating foil can be positioned between the support base and the electroluminescent foil to protect the graphic from excessive heat during manufacture of the illuminated cover. However, if no graphic is included, then the second insulating foil can be omitted. Likewise, if the graphic would not be damaged by the heat, the second insulating foil can be omitted. The support base and the second insulating foil have a first opening therethrough for insertion of an electrical connector to connect the electroluminescent foil to an electrical power source so as to provide power to the electroluminescent foil. The support base, the first and second insulating foils, and the electroluminescent foil have a second opening therethrough for insertion of a control key of a device to be covered by the decorative cover.
A covered electronic device in accordance with the present invention further includes a printed circuit board having a plurality of electronic components mounted on it which are electrically interconnected to form an electronic unit, such as a cellular telephone. The electrical components include a control key for the electronic unit, with the control key extending through the second opening in the decorative cover. The covered electronic device further includes a connector extending into the first opening of the decorative cover to connect the electroluminescent foil to circuitry on the printed circuit board so as to provide electrical power to the electroluminescent foil.